1. Field Of The Invention
This invention relates to internal combustion engines.
2. Description Of The Prior Art
Internal combustion engines of the basic Otto type which are commonly used at present, employing poppet type valves, have certain basic drawbacks which, in spite of many years of research and development, have prevented the efficiency of such engines from being increased beyond the order of 30 percent. For example, poppet valves are generally restricted in size and permissible opening due to camshaft and other limitations and have a constant opening regardless of the engine speed and other variable operating conditions. Therefore, the design of present internal combustion engines represents a compromise of various factors. Also, although such an engine may have a peak efficiency at a certain speed, the efficiency falls off as the speed is increased or decreased beyond such critical point.
Engines incorporating rotary valves have proven superior in certain respects in that they can be made with larger valve openings and with different shaped openings and are not limited by restrictions imposed by camshaft configurations, such as the necessary rise and fall times of the poppet valve operating cams.
Also such rotary valve engines are basically simpler in that they eliminate the need for valve operating trains including valve springs, cam shafts, etc. However, such prior rotary valve engines present other difficulties, such as lack of lubrication and binding tendencies, which have prevented them from being universally accepted even though they represent the possibility of increased efficiency. In addition, such prior rotary valve designs cannot be applied to present engine block assemblies but require a complete redesign of the entire engine.
Furthermore, even such prior rotary valve engines suffer from a relatively low efficiency, even though this may be somewhat higher than poppet type engines.
Accordingly, a principal object of the present invention is to increase the operating efficiency of an internal combustion engine.
Another object is to simplify the construction of an internal combustion engine.
A further object is to provide a rotary valve mechanism which can be applied to the engine block of a conventional poppet valve type internal combustion engine.
A further object is to provide an improved cooling system for a rotary valve type engine.
A further object is to save fuel by using dual combustion chambers where the relationship of fuel density to total cylinder displacement is not the determining factor of engine efficiency.